Wednesday, 22 October 2008

Creation or evolution - do we have to choose? - chapter 3 (What do we mean by evolution? Dating, DNA and Genes)

After 22 pages intended to give an overview of the Christian idea of creation, we are now treated to 104 to give us an overview of the idea of evolution. Perhaps this is necessary because the intended readership of the book will be assumed to already know more about the former than the latter. On the other hand, it is an interesting reflection of a theme that runs throughout the book: DA is a very orthodox evolutionist, and very reluctant to tweak with anything that forms the present consensus in the mainstream scientific community; but as regards orthodox Christian theology, it has much less that is certain and can be tweaked and adapted quite at will.

This chapter, as the title suggests, introduces us to dating, DNA and genes; the next two chapters explain the topics of "natural selection and reproductive success" and "Speciation, fossils and the question of information", before a chapter addressing some objections ties the summary up.

I am a theologian and logician, not a biologist, so if DA has made any subtle errors in the finer points of explaining DNA and genes, I won't be detecting it any time soon. Much of this kind of material is uncontroversial, though DA doesn't bother to point that out. The ways in which DNA and genes can be observed to operate in the world today can be observed by everyone, and folded into a variety of different possible theories about the past. That outwardly quite different organisms have various similarities in their genes can be explained by many different and incompatible theories. Perhaps those organisms have a common ancestor and the similarities have been copied down the years and the divergent paths of Darwinian evolution. Perhaps those organisms have a common designer who intended his highest creature, man, to study and understand the living world, and so for that and other reasons used similar designs in many of his creatures. Perhaps it's just a massive coincidence. The point is that the observation itself is a neutral fact; how we decide which theory it points to, or maybe none of the above, has to be decided on other grounds.

This is a good point to mention, then, that at no point in his book does DA explain to his readers that scientific research takes place in terms of paradigms. There is a model, and research is done to explore that model, which is then confirmed, or adapted in minor or major ways, or even scrapped, or perhaps we just put the research on the shelf because it puzzles us too much and we don't know what to do with it. Only a miniscule number of research scientists genuinely make a new advance; the vast majority are involved in doing work that simply assumes thetruth of a particular paradigm, or seeks to confirm it or possibly to tease it out a little bit. When it comes to comparing two competing paradigms (such as Darwinism or special creation), you can't just point out that your paradigm "explains stuff"; that is not evidence of superiority. Evidence of superiority comes when you show that your paradigm explains stuff better than the other one across a wide range of data. Alexander, though, despite a few critiques of modernist thought here and there, allows his reader to go away thinking that science is simply a giant consensus, slowly, objectively and relentlessly grinding its way from neutral assumptions to the discovery of all (natural) truth. That's classic Darwinist rhetoric; the simple reader must not be allowed to think in terms of controlling world-views or paradigms, because the suggestion that philosophy or personal prejudice might play a part in scientists' work, or that they simply might be just barking up the whole wrong tree from the beginning in any particular area, would lead to evolution being given a more objective scrutiny than it could survive. Hence, our chapters introducing evolution simply describe whatever the present consensus is, and keep the whole matter of paradigms and competing models or world-views conveniently hidden.

It is instructive to notice just how thorough-going DA's debt to enlightenment thinking is in these chapters. Biblical truth and scientific truth are, in his mind, in effect two hermetically sealed sources of truth. Yes, the Christian scientist may pause during his work to praise the Creator for what wonderful things he has made; but Biblical truth is never allowed to set any boundaries or limits in his study - this would be a category mistake. Hence we have two self-contained chapters on creation, and now some on evolution, and these can stand quite independently of what's gone before. Simply put, DA swallows the enlightenment fallacy of a "neutral" science hook, line and sinker. There is not a word to show us any awareness of the Christian idea of theology as the "queen of the sciences", where the Word of God is the ultimate source of revelation and authority, by which every external idea must be scrutinised and have its limits defined.

Hence it is, then, that in the section arguing for a very large age for the creation, there is simply no discussion of what limits Scripture puts upon it - even whether it does. There is nothing on this in the whole book. This fits in with the way DA has been going - the Bible tells us spiritual truths, but science tells us ones about the physical world. We noted in the last chapter that the question of whether Scripture tells us historical truths is one that DA simply side-steps. Of course, enormously long ages are needed to fit in the evolutionary hypothesis, so DA piles up various lists of things that are really really old. It's another exercise in moving swiftly on conveniently omitting to discuss any of the difficulties. If there really was a global flood, then many of the assumptions used in these things are simply wrong. If you find a nearly full bucket in my bathroom under a dripping tap, you might measure the rate of dripping and then calculate how long it took to get so full - a few weeks. In fact I filled that bucket myself and then turned the tap off 5 minutes ago and it's got a little drip. By giving you a key to the past, I've shown you that you're going wrong if you just do some sums that assume that as things are now, so they have ever been. The word of God is our key to the past. If there was a world-wide flood, as it says, then we have to factor that into our calculations; we can't simply assume that present processes can unlock our past if we just wind the clock back and do the sums. DA, though, follows the secular model totally: only data from the physical present can control our interpretation of the past, and the Bible must be treated as if it either doesn't exist or says nothing on the matter. Being a professing evangelical, DA plumps for the latter: dating and the age of the this or that is fixed by science, only by science, and the Bible is simply a book with nothing significant to say on matters of ancient history. We have here again the practical outworking of the "two books" fallacy (whether DA actually believes it or not): science teachesus about history and the physical world, the Bible teaches us spiritual values.

This chapter is preliminary. There's some material about encoding and non-encoding sections of our DNA. This is intended to pave the way for DA's proof of common ancestry. All that to come.